Spiral wound retaining rings are well known in the art. These rings consist of two or more turns of a flat material wound to provide a continuous coil. The typical ring is wound two times, the end of the material not quite reaching the beginning. Thus, about 80-90 percent of the ring is comprised of a double layer, the remaining 20 percent is a single layer. This single layer area is necessary to facilitate insertion and removal of the ring. To insert an interior ring the ends are pulled together to temporarily decrease the diameter of the ring, this enables the ring to fit into the cylinder. Once the ring is placed into the groove and the ends released the ring springs back to its larger diameter to stay securely in position. The single layer area provides enough clearance to pull the ends closer together without any overlap since a three layer section would not fit into the groove.
Since the standard retaining ring is comprised of a single layer over from 10-20 percent of its surface the load that is applied to the ring and therethrough to the groove in the retaining cylinder is distributed over from 80-90 percent of the surface of the ring and groove. For most applications this poses no difficulty since the ring and groove can be designed to withstand the entire load over less than their entire surface. However, in critical situations it may be impossible to make the groove so strong and consequently, the grooves may deform when a load is applied. For example, in a particular rocket engine a groove constructed of fiberglass could not withstand a load distributed over only 80-90 percent of the groove. However, the groove could and did withstand the same load when a retaining ring with decreased single layer area was used to distribute the load over approximately 98 percent of the ring and groove surfaces.
It is therefore an object of this invention to provide a retaining ring with decreased single layer area.
Another object of the invention is to provide a retaining ring that distributes a load over a greater proportion of its surface than standard retaining rings.
These and othe objects of the present invention and the advantages attendant therewith will be readily understood when the specification is taken in conjunction with the attached drawings to which it relates.